Pump



J. J. LYTH Sept. 15, 1953 PUMP 2 Sheets-Sheet 1 Filed May 29, 1950 hire/Mal Ja/m J. Lyf/z By Sept. 15, 1953 J. J. LYTH 2,651,997

PUMP

Filed May 29, 1950 2 Sheets-Sheet 2 Patented Sept. 15, 1953 UNITED sures PATENT omcr.

PUMP John J. Lyth, Valleyfield, Quebec, Canada Application May 29, 1950, Serial No. 165,051

9 Claims. (01. 103-44) This invention relates to pumps and especially to pumps for handling liquids or suspensions which cannot be pumped satisfactorily, or at all, by ordinary pumps because of corrosive or abrasive or clogging effect of the liquid or suspension on the working parts of ordinary pumps, or because the liquid or suspension would be contaminated by the material of ordinary pumps.

Pumps of the above type customarily comprise separate passages for an impelling liquid and for an impelled liquid or suspension, separated by a member movable by the impelling liquid to move the impelled liquid, such member being usually a flexible diaphragm. Pumps of this type heretofore used have a number of .practical disadvantages, such as complicated and expensive construction, difficulty in renewing diaphragms, the form and arrangement of the diaphragms, and unbalanced or otherwise faulty transmission of power from the impelling liquid to the impelled liquid.

The primary object of the present invention is to provide a pump of the aforesaid type which is simple and inexpensive in construction; in which the impelled liquid passages are readily accessible for cleaning and the diaphragms for cleaning and renewal without disturbing any of the connections of the pump. A concomitant object is to provide a diaphragm pump in which the diaphragms and the movement of impelled liquid in the pump may be under constant observation. A further object is to provide a pump so constructed that the body thereof may be formed of glass or ceramic material. A still further object is to provide a double diaphragm pump in which the pressure of impelling liquid is applied to the best advantage and equally to both diaphragms. Another object is to provide a diaphragm which will be exceptionally durable. Various other objects and the advantages of the invention may be ascertained from the following description and the accompanying drawings.

Broadly speaking, the invention consists in a pump comprising a chamber for an impelled liquid and chambers for an impelling liquid arranged on opposite sides of the impelled liquid chamber and separated therefrom by circular, circularly corrugated diaphragms, and a plunger pump associated with said impelling liquid chambers in suchwise as to deliver exactly equal flows of liquid to the two chambers, the diaphragms being readily removable for cleaning and replacement; the form of said chambers being such as to permit of making them of glass, ceramic or moulded plastic, and also being such as to prevent the accumulation of air, vapour or solids in the impelled liquid chamber.

In greater detail, the invention consists in the features and combinations of features herein disclosed, together with all such modifications thereof and substitutions of equivalents therefor as are within the scope of the appended claims.

In the accompanying drawings which illustrate embodiments of the invention now preferred but to the details of which the invention is not limited:

Fig. 1 is a view of the pump, half in side eleva-- tion and half in section on the line 1-4 of Fig. 2..

Fig. 2 is a view of the pump, half in end eleva-- tion and half in section on the line 2-2 of Fig. 1.. Fig. 3 is a view similar to Fig. 1 illustrating a.

modification.

Referring more particularly to the drawings. ll designates a preferably cylindrical or tubular body member, the length of which is preferably" materially less than the diameter thereof, having: at least one hollow neck [2 communicating with: the interior thereof, and a hollow foot l3, the: interior of which is completely isolated from the interior of the body. In Fig. l the body is showrr provided with a single neck I2 leading from the: highest point of the body and in Fig. 3 it is shown as having an additional neck I! leading from the lowest point of the body. The neck l2 preferably extends vertically upward from the body and, for compactness, the neck I2 may extend laterally with downward inclination, whereby the distance between the top of the neck 12 and the bottom of the foot l3 may be the same in both forms and permit of interchangeability without altering the elevation of a pipe connected to the neck l2. The interior of the body constitutes an impelled liquid chamber l4. When the liquid to be handled is free from suspended solids which might accumulate in the body, the neck [2 alone may suffice for both ingress and egress of liquid and is located at the uppermost point of the body to permit escape of air or vapour which, if it could accumulate, would seriously interfere with efficient pumping operation, as will be readily understood. For dealing with suspensions from which solid matter might settle in the body, the necks l2 and l2 provide for separate egress and ingress, respectively, of the suspension, the ingress preferably being at the bottom, as shown, so that incoming suspension will. pick up and carry with it any solids tending to settle .out; and the egress being preferably at the top, for the reason already given. Obviously, the. direction of flow may be reversed if desired.

It will be noted that, except where the neck; or necks and the foot attach, the wall of the body combined with the cylindrical form, produces a.

mass in which little or no undesirable internal. stress will be produced on cooling from a high;

the strength of the body if moulded of glass or a,

ceramic. A plastic suitable for use in making the body, known under the tradanameflLuciteflhas adequate mechanical strengthand rigidity. is...

inert to most acids and alkalis and has the added advantage of being transparent. plastic or transparent glass is used as the body mate ia i, e nd t ens w th n e bo m y e kept under, constant observation duringoperation f h ma.

If desired, the inner surface of; the body. and its,.necks.l 2.,and 12% may be provided withajining EFSbfmat rialadapted to resist corrosion bythe impelled. liquid, or to protect the liquid against contamination by the material of the body, The nature of; the liningmaterial will depend n the nature of the liquidto,be handledbythepump. Materials suchas lead,- aluminum, silver, vulcanite, vitreous enamel, wax, plastic or even glass may besused, the ,selectiondependingon thenatures of the impelled liquid and of the body-material The lining contemplated is, in one 1 piece covering the entire interior. of the body-and neck or necksand xtehdingasuitable distance overthe end surfacesofthe body andmeck or, necks,

as indicatedat. It, so as to,protect;these surfacesi against corrosion by.;liquid entering betweenthem;

and elements abutting them.

The interior ll of the foot l3 tapers up-yardlyv and communicates at itsupper end with two equal and oppositely extending, passage l tlsleacling to the ends of the body. The-combined cross-secs tional areas ofthe two passages i8.-:are;substan tially equal to themaximum cross-sectional area of the foot interior 1 1.

Dished or .cup -Ishaped concave endcaps. I9, each of adepth equal tQsubStantiaIly half the, length of the body, are provided for the body; and; have fiangesZQeXtending radia l beyond the, body and formed with apertures 2! beyond, the I circumferenoe of the-body. Attachingbolts 22; extend from cap. to, cap; and through the flange; apertures 21' and are provided with nuts- :23Jaear v ing a inst the outer, or remote, surfaces of the cap, flanges 2fl, whereby.-the ;body maybetightly;

If thespacing of thebolts 22.so requires thebody may be, formed with passages adjacenttheneck I 2. and foot:,l3,,- through which certainof the boltsmay. pass.,; The caps I9 are provided with portslfiregistering: with the bodypassages l8 and communicating. the interiors 25. of bothcaps with .tl1e-.foot p as sage ll, these interiorsifi bein rimpelledliquid chambers. Theendcaps may be formed ofany.

clamped between the caps.-

suitable material, such as me,tal,, vulcanite, plas; tic or glass.

A substantially circular, flexible, and elastic diaphragm 21 is DITQl idfid at eachsendlof. thebody. H, the peripheral portion of, each; diaphragm;

extendingv between the end of. thebody; and the adjacent surface of the. closure. cap;- I 9 stherefor.

These diaphragrns are formed. with circular cor-.

rugations concentric with pne another and {Withpl the diaphragm sThe diaphragm; separates the;

were 1 1 .14 4 same-ton immanent If transparenta impelling liquid chambers 26 of the caps. The peripheral portions of the diaphragms act as gaskets between the caps l9 and the ends of the body II to ensure liquid tight joints. To facilitate making of such joints between the caps and body around the passages l8, the diaphragms preferably have; radially extending portions 28 formed with openings 29 in register with the passages l8 and ports 25. The diaphragms may be formed of any suitable flexible and elastic material which is inert and impervious with respect to the impelled liquid in chamber 14 and the impelling liquid-in chambers 26. Physically suitablematerialsarerubber and certain of the plastics now readily available on the market. One such-plastic is that known under the trade name Tygon and has the additional advantage of bein t ansnar nt.

Each impelling fiuidphamber. 26 isvprovided at i s: highest: point.- with an airvent cockv 30' and one;,o f--these mayhaye a: funnel-shapedoutlet 3i to iacilitat fillingi the chambers 26,.with the impelling fluid.

The-structure heretofore;- described is mounted by Ir lear 1s;.'of its foot; I 3 -011 a closed reservoir 32 forimpelling. liquid, the interior ll; of the foot communicating;Withthe interior, of the reservoir at the top;th ereof-, One'end of: the reservoir is closed by aplate 33; having; atubular extension 34 'projecting into; the;reservoir and provided in its innercportion with-a=replaceablebushing 35 ofzantiirictionmaterial, suchqas brassor bronze, and inits outer portion withapacking gland 36, also of antifriction material, Pack-ingt'l is compressed between they bushingand; gland to make liquid-tight: contact ;with;a, plunger 38 adapted to bereciprocatedin :the;bushing and gland by any suitable mechanism.

When installed; the pump ,-is associated with a conduit for-impelled liquid communicating with the'chamber [Athrough-the neck [2; or necks i2 and-12 and-:having check'valves, one on each sideof-the pump, to. control the direction of liquid flow;v With, the plunger: 38, at midstroke, the reservoir 32, chambers ;26 and; connecting passages are completely filledwith-an impelling liquid,.such as water, both; vent cocks, 30being open and the-liquid beingintroduced through the fun nel- 3|. As ,the' necktpassage l7 "leads from the highest point of, the; reservoir, entering; water displacesairin the reservoir'and; in the chambers 26- so: that none remains-in thesystem to inter fer-e with, thepumpingaction. When the system is-.fil1ed,;b0th cocks 39-;are closedg andthe water becomes a hydraulic'transmission between the plunger ,3 8rand thediaphragms;

In operation, when-the plunger moves inwardly of the reservoir it forces liquid. from the reservoir through the foot; passage 11; bodypassages l8 and cap ports 25,into,-the;chambers 26, thereby displacing liquidtherein; to force the diaphragms toward; one another: and; into the chamber !4, thus displacing, liquid from, the ,chamber I 4 into theconduit'to whiclrit isconnected. Whenthe plungermoves outwardlyof thereservoir, it draws back; the, impelling; fluid frommthe chambers 26' oneganother to .draw, impelledrliquid into the chamber lk Thescheck valves associated with the, pump.- ensuresunidirectional liquid flow in the. conduit;

The {volumetric v; displacement of the plunger determinesszthesamount of 'flexionof the diaphragms and by varying::the stroke -orthediameter, aori-bothi strokesand: diameter; of-I the plunger, the displacement oi the diaphragms may be varied from nothing to a maximum at which the diaphragms are, in their central portions, substantially flattened against one another or against the caps according to the direction of plunger movement. The number and depth of the corrugations are such that at maximum displacement of the diaphragms the corrugations merely tend to be straightened out by flexion and the diaphragms are not subjected to destructive radial tension. The cross-sectional areas of the two passages 13 being equal, and together equalling the crosssectional area of the foot passage ll, ensures that the flows of impelling liquid to and from the two chambers 26 are always equal, thus ensuring equal displacements of the diaphragms, while the depth of the caps being substantially half the length of the body ensures that the maximum inward and outward displacements of the diaphragms are equal and that the diaphragms cannot be excessively displaced in. either direction.

The removal of nuts 23 at either end of the pump releases both caps I9, which may be removed without displacing any of the connections of the pump and will enable easy removal of both diaphragms for cleaning or renewal and also will aiiord unobstructed access to the chamber I4. This feature is especially important if the pump is used for foodstuffs and must be cleaned at requent intervals of time.

The removable sleeve 34 permits of very quickly altering the capacity of the pump by substituting a sleeve carrying a plunger of different diameter, complete with packing already in place. Also, in event of leaky packing, a replacement assembly of sleeve, packing and plunger can be inserted more quickly than packing alone can be replaced.

As previously pointed out, the body and caps, or either body or caps, can be made of transparent material, such as glass or plastic, and the diaphragms of transparent plastic, so that the flow of both impelling and impelled liquids and the physical condition of the diaphragms may be under constant observation. This is of importance in cases where the impelled liquid would be detrimentally affected by leaking of impelling liquid thereinto.

Having thus described my invention, I claim:

1. A diaphragm pump comprising a short tubular body; internally concave end caps for said body; flexible diaphragms engaged at their edge portions between the body and the end caps, dividing the space enclosed by the body and end caps into a single inner chamber for impelled liquid defined by said body and both said diaphragms and a pair of substantially equal outer chambers for impelling liquid, each defined by one of said end caps and one of said diaphragms; bolts passing from cap to cap whereby the diaphragms and body are clamped between the end caps; a passage leading into said inner chamber at the highest point thereof; means for admitting impelling fluid under pressure into both said outer chambers simultaneously, whereby said diaphragms are displaced toward one another, with expulson of impelled liquid from the inner chamber, and for withdrawing impelling liquid from both said outer chambers simultaneously, whereby said diaphragms are displaced away from one another with indrawing of impelled liquid into said inner chamber.

2. Structure according to claim 1 in which the means for admitting impelling liquid includes a hollow neck supporting the body from below and providing an upwardly extending impelling liquid passage and a pair of equal branches from the upper end of said passage, leading to the ends of the body; and equal ports at the lowest points of said end caps communicating with said branch passages, whereby equal amounts of impelling liquid are supplied to said outer chambers and equal amounts are withdrawn.

3. Structure according to claim 1 in which the depth of each impelling liquid chamber in the axial direction of the body is substantially half the length of the impelled liquid chamber in the axial direction thereof, whereby maximum inward and outward displacements of the diaphragms are limited to equality.

4. A pump according to claim 1 in which the caps are transparent to permit observation of the diaphragms.

5. A pump according to claim 1 in which the caps and diaphragms are transparent to permit observation of the flow of impelled liquid in the body.

6. A pump according to claim 1 in which the body is transparent to permit observation of the impelled liquid therein and of the diaphragms.

l. A pump according to claim 1 in which the body is composed of material selected from the group of materials consisting of glass and ceramics.

8. In combination with structure according to claim 1, flanges on said caps extending radially outward of the body and apertured for passage of said bolts, whereby the bolts are disposed externally of the body.

9. A diaphragm pump comprising a reservoir for impelling liquid having an opening at its highest point; a substantially cylindrical body of length materially less than its diameter having a hollow neck communicating with the highest point of the body interior; a hollow foot supporting the body on the reservoir, the interior of said foot communicating with the interior of said reservoir through the top opening thereof; passages leading from the interior of the foot to the ends of the body; dished end caps for the body, having ports registering with said passages and flanges projecting radially beyond the body; flexible diaphragms separating the interior of the body from the interiors of said end caps and having peripheral portions entering between the end surfaces of the body and the end caps; bolts passing from cap to cap through the cap flanges and clamping the diaphragms between the body and caps and the caps to the body; the volumes of the chambers defined between the end caps and the diaphragms being substantially equal and together substantially equal to the volume of the body chamber between the diaphragms; and valved openings at the highest points of the end caps whereby the reservoir, passages, and spaces between the end caps and diaphragms may be completely filled with impelling liquid and air completely expelled therefrom.

JOHN J. LYTI-I.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 225,930 Hoster Mar. 30, 1880 1,489,143 Nuss Apr. 1, 1924 1,851,666 Evans Mar. 29, 1932 2,402,524 Corydon June 18, 1946 

